1. Field of the Invention
The invention pertains to the disposal of hexachlorodisilane residues.
2. Description of the Related Art
Hexachlorodisilane is being used to an increasing extent in silicon chip manufacture. It is frequently deposited via the gas phase using CVD processes. This, however, leaves vapors which have to be treated after leaving the deposition chambers.
US 2009/0104100 A1 describes the treatment of hexachlorodisilane-containing offgases. This treatment involves first oxidizing the offgas with exclusion of moisture in a complex apparatus, before it is passed through a scrubber filled with water.
The reaction of hexachlorodisilane with water or moisture generally releases HCl gas, which attacks the silicon-silicon bond. This gives rise to Si—H— containing hydrolysis products which decompose on mechanical contact, for example as a result of friction, with sparking. The hydrolysis products in solid form can even decompose under water with sparking.